OpenWRT One device tree overlay

Author: vidplace7

openwrt-one-mikrobus-spidev/Makefile

@@ -0,0 +1,53 @@
+# Inspired by OnionIOT's `onion-dt-overlay` package
+# https://github.com/OnionIoT/OpenWRT-Packages/tree/openwrt-23.05/onion-dt-overlay
+
+include $(TOPDIR)/rules.mk
+include $(INCLUDE_DIR)/kernel.mk
+
+PKG_NAME:=openwrt-one-mikrobus-spidev
+PKG_URL:=https://github.com/openwrt/openwrt/pull/17399
+PKG_VERSION:=1.0
+PKG_RELEASE:=1
+
+DTC=$(LINUX_DIR)/scripts/dtc/dtc
+
+include $(INCLUDE_DIR)/package.mk
+
+# @TARGET_mediatek_filogic
+define Package/openwrt-one-mikrobus-spidev
+	TITLE:=openwrt-one-mikrobus-spidev
+	DEPENDS:=+kmod-spi-dev +kmod-fs-configfs @aarch64
+endef
+
+define Package/openwrt-one-mikrobus-spidev/description
+	DT Overlay for OpenWRT One MikroBus spidev support
+endef
+
+define Build/Compile
+	$(DTC) -b 0 -@ -O dtb ./files/mt7981b-openwrt-one-mikrobus-spidev.dtso -o $(PKG_BUILD_DIR)/mt7981b-openwrt-one-mikrobus-spidev.dtbo
+endef
+
+define Package/openwrt-one-mikrobus-spidev/install
+	$(INSTALL_DIR) $(1)/lib/firmware/device-tree/overlays
+	$(INSTALL_DATA) $(PKG_BUILD_DIR)/mt7981b-openwrt-one-mikrobus-spidev.dtbo $(1)/lib/firmware/device-tree/overlays/mt7981b-openwrt-one-mikrobus-spidev.dtbo
+	$(INSTALL_DIR) $(1)/etc/init.d
+	$(INSTALL_BIN) ./files/dtbo-mikrobus-spidev.init $(1)/etc/init.d/dtbo-mikrobus-spidev
+endef
+
+define Package/openwrt-one-mikrobus-spidev/postinst
+#!/bin/sh
+if [ -z "$$$${IPKG_INSTROOT}" ]; then
+	/etc/init.d/dtbo-mikrobus-spidev enable
+	/etc/init.d/dtbo-mikrobus-spidev start
+fi
+endef
+
+define Package/openwrt-one-mikrobus-spidev/prerm
+#!/bin/sh
+if [ -z "$$$${IPKG_INSTROOT}" ]; then
+	/etc/init.d/dtbo-mikrobus-spidev stop
+	/etc/init.d/dtbo-mikrobus-spidev disable
+fi
+endef
+
+$(eval $(call BuildPackage,openwrt-one-mikrobus-spidev))

openwrt-one-mikrobus-spidev/files/dtbo-mikrobus-spidev.init

@@ -0,0 +1,34 @@
+#!/bin/sh /etc/rc.common
+
+START=99
+STOP=10
+
+OVERLAY_NAME="mt7981b-openwrt-one-mikrobus-spidev"
+OVERLAY_PATH="/sys/kernel/config/device-tree/overlays/$OVERLAY_NAME"
+DTBO_FILE="/lib/firmware/device-tree/overlays/$OVERLAY_NAME.dtbo"
+
+start() {
+    # Mount configfs if not already mounted
+	grep -q /sys/kernel/config /proc/mounts || \
+		mount -t configfs configfs /sys/kernel/config
+    
+	[ -d /sys/kernel/config/device-tree/overlays ] || {
+		log "userspace device tree overlay support not found."
+		return 1
+	}
+
+    # Create overlay directory and load the dtbo
+    if [ -f "$DTBO_FILE" ] && [ ! -d "$OVERLAY_PATH" ]; then
+        mkdir -p "$OVERLAY_PATH"
+        cat "$DTBO_FILE" > "$OVERLAY_PATH/dtbo"
+        log "Loaded device tree overlay: $OVERLAY_NAME"
+    fi
+}
+
+stop() {
+    # Remove the overlay
+    if [ -d "$OVERLAY_PATH" ]; then
+        rmdir "$OVERLAY_PATH" 2>/dev/null
+        log "Unloaded device tree overlay: $OVERLAY_NAME"
+    fi
+}

openwrt-one-mikrobus-spidev/files/mt7981b-openwrt-one-mikrobus-spidev.dtso

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+/*
+ * Copyright (C) 2025
+ * Author: Mark Birss <mark.birss@gmail.com>
+ */
+
+/dts-v1/;
+/plugin/;
+
+/ {
+        compatible = "openwrt,one", "mediatek,mt7981";
+
+        fragment@0 {
+                target = <&spi1>;
+                __overlay__ {
+                        status = "okay";
+                        #address-cells = <1>;
+                        #size-cells = <0>;
+
+                        spidev@0 {
+                                compatible = "silabs,si3210";
+                                reg = <0>;
+                                spi-max-frequency = <52000000>;
+                        };
+                };
+        };
+};